Radio transmitters amplify input signals. It is desired that the gain of such transmitters be linear for the entire range of input signals. A common architecture of recently proposed baseband power amplifier linearizers includes a digital nonlinear gain block, usually called a predistortion block, inserted in the transmitter chain prior to upconversion stages. The predistortion block may be continuously adapted to approximate as closely as possible the inverse nonlinear complex gain of the following transmitter stages up to the power amplifier. Feedback may be provided to the predistortion block. However, such feedback may result in unstable transmitter operation. There is need to stabilize operation of the radio transmitter while accounting for nonlinearities of power amplifiers.